// 表情包转字符串
export const utf16toEntities = (str) => {
			var patt=/[\ud800-\udbff][\udc00-\udfff]/g; // 检测utf16字符正则
			str = str.replace(patt, (char) =>{ 
			    var H, L, code; 
			    if (char.length===2) { 
			        H = char.charCodeAt(0); // 取出高位 
			        L = char.charCodeAt(1); // 取出低位 
			        code = (H - 0xD800) * 0x400 + 0x10000 + L - 0xDC00; // 转换算法 
			        return "&#" + code + ";"; 
			    } else { 
			        return char; 
			    } 
			}); 
			return str; 
			}

// 字符串转表情包			
export const uncodeUtf = (str) => {
		var reg = /\&#.*?;/g;
		   var result = (str + '').replace(reg,(char) =>{
		       var H,L,code;
		       if(char.length == 9 ){
		           code = parseInt(char.match(/[0-9]+/g));
		           H = Math.floor((code-0x10000) / 0x400)+0xD800;
		           L = (code - 0x10000) % 0x400 + 0xDC00;
		           return unescape("%u"+H.toString(16)+"%u"+L.toString(16));
		       }else{
		           return char;
		       }
		   });
		   return result;
		} 